1. Field of the Invention
The invention relates to a toothbrush with a special handle of dual material construction that conforms to hand pressure, improves grip and has a radial anti-slip benefit.
2. The Related Art
Over the past several years a number of new toothbrushes have been introduced into the market. For instance, the Colgate-Palmolive Company now sells a product known as the Precision brush. Besides a special brushhead, the Precision product in one version includes a rippled handle whose upper and lower surfaces are covered with a material different from that of the lateral and front portions of the handle. Only small differences in hardness distinguish the upper/lower surface material (86 Shore Hardness) from the lateral/front material (95-100 Shore Hardness). U.S. Pat. No. Des. 342,160 (Curtis et al.) and U.S. Pat. No. Des. 342,162 (Curtis et al.) cover the design aspects of the Colgate-Palmolive product.
A similar design concept has been incorporated into the Crest Complete brush, a product of the Procter & Gamble Company. FIG. 1 of WO 91/19437 (Volpenhein et al.) illustrates the Crest Complete brush. A substantial portion of both the upper and lower surfaces of the handle are covered by strips of a material (89 Shore Hardness) leaving the lateral sides (95-100 Shore Hardness) uncovered.
Dual material handles have also been introduced by the SmithKline Beecham Corporation under the Aqua Fresh trademark. Similar to its competitors, a very substantial part of the upper and lower surfaces of the handle are covered by a material (88 Shore Hardness) different from the remaining material (95-100 Shore Hardness) of the handle. A related brush is illustrated in U.S. Pat. No. Des. 328,977 (Halm).
U.S. Pat. No. Des. 334,288 (Witzig-Jaggi) describes a dual material toothbrush wherein material on an upper surface of the handle exhibits a sloping change of thickness.
Utilization of dual materials has been mainly for aesthetic purposes, and only secondarily meant to improve grippability of the handle.
Flexible walls have also been incorporated into toothbrushes that include hollow reservoirs for stirring and delivering toothpaste. Disclosures of this type of technology may be found in French Patent 2,680,456 (Cristea) and French Patent 2,680,656 (Charpentier).
Another recent development in toothbrush technology has been the use of corrugated handles. WO 93/15627 (Halm) describes a handle with an integral corrugated core surrounded by an elastomeric region. The corrugated core provides resiliency to the handle. This corrugation has also been utilized in DE 4,222,931 (Henkel). Therein is reported a ribbed handle with each of the ribs being of square cross section.
There have been many innovations in this area as can be seen through the above briefly described patents. Nevertheless, there remains room for improved models.
Accordingly, it is an object of the present invention to provide a toothbrush with a handle having sections sufficiently resilient to conform to a users fingers upon application of pressure.
It is another object of the present invention to provide a toothbrush that can be manipulated with less fatigue than typical commercial toothbrushes.
It is still another object of the present invention to provide a toothbrush with a feature that reduces both radial and longitudinal slip and that allows for improved grippability no matter where along a target circumference a user places finger pressure.